In many cement mixing applications, dry cement powder is conveyed pneumatically, and significant quantities of the associated air becomes entrained within the mixed cement slurry. This entrained air creates adverse mixing conditions, including inaccurate slurry density measurements, higher frictional pressures, and potential loss of prime in pumps used to move the cement slurry. Entrained air also can cause significant foaming along a surface of the mixed cement slurry.
Entrainment and foaming are sometimes controlled through the use of chemicals. In other applications, entertainment and foaming are reduced by circulating fluid through a centrifugal separator by which some of the entrained air is exhausted. In many applications, however, addition of chemicals can be detrimental, and centrifugal separators are not able to reduce foam on the fluid slurry surface.